TOI-5344 b: A Saturn-like planet orbiting a super-Solar metallicity M0 dwarf

• Published in: arXiv.org 2023-11
• Main Authors: Han, Te, Robertson, Paul, Kanodia, Shubham, Cañas, Caleb, Lin, Andrea S J, Stefánsson, Guðmundur, Libby-Roberts, Jessica E, Larsen, Alexander, Kobulnicky, Henry A, Mahadevan, Suvrath, Bender, Chad F, Cochran, William D, Endl, Michael, Everett, Mark E, Gupta, Arvind F, Halverson, Samuel, Hearty, Fred, Monson, Andrew, Ninan, Joe P, Roy, Arpita, Schwab, Christian, Terrien, Ryan C
• Format: Article
• Language: English
• Subjects: Buttes; Circumstellar habitable zone; Deposition; Extrasolar planets; Metallicity; Orbits; Photometry; Planet detection; Planetary mass; Radial velocity; Red dwarf stars; Transit
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2310.20634

We confirm the planetary nature of TOI-5344 b as a transiting giant exoplanet around an M0 dwarf star. TOI-5344 b was discovered with the Transiting Exoplanet Survey Satellite photometry and confirmed with ground-based photometry (the Red Buttes Observatory 0.6m telescope), radial velocity (the Habitable-zone Planet Finder), and speckle imaging (the NN-Explore Exoplanet Stellar Speckle Imager). TOI-5344 b is a Saturn-like giant planet (\(\rho = 0.80^{+0.17}_{-0.15}\ \text{g cm}^{-3}\)) with a planetary radius of \(9.7 \pm \ 0.5 \ \text{R}_{\oplus}\) (\(0.87 \pm \ 0.04 \ \text{R}_{\text{Jup}}\)) and a planetary mass of \(135^{+17}_{-18} \text{M}_{\oplus}\) (\(0.42^{+0.05}_{-0.06} \ \text{M}_{\text{Jup}}\)). It has an orbital period of \(3.792622 \pm 0.000010\) days and an orbital eccentricity of \(0.06^{+0.07}_{-0.04}\). We measure a high metallicity for TOI-5344 of [Fe/H] = \(0.48 \pm 0.12\), where the high metallicity is consistent with expectations from formation through core accretion. We compare the metallicity of the M-dwarf hosts of giant exoplanets to that of M-dwarf hosts of non-giants (\(\lesssim 8\ \text{R}_{\oplus}\)). While the two populations appear to show different metallicity distributions, quantitative tests are prohibited by various sample caveats.